Centrifugal floor washing machine



Feb. 2, 1954 w. ENGEL CENTRIFUGAL FLOOR WASHING MACHINE Filed Jan. 16, 1950 5 Sheets-Sheet 2 In vcnfor WEI? 6/ 42y Patented Feb. 2, 1954 UNITED STATES PATENT OFFICE one-half to Lina Teichmann,

land I Geneva, Switzer- Application January 16, 1950, Serial No. 138,718

Claims priority, application Switzerland January 20, 1949 9 Claims.

The present invention relates to a centrifugal machine for cleaning substantially flat surfaces, such as paved domestic yards and similar areas, comprising a container intended to contain a cleansing liquid, and at least one rotary rubbing device towards the centre of which this liquid is supplied by gravity, to be then distributed over the surface to be cleaned by the centrifugal action due to the rotation of the rubbing means.

An important object of this invention is to provide, in a floor washing machine of the kind above mentioned, a rotary collector comprising a coned lip normally contacting the floor and entirely surrounding the rubbing device, a filter carried by a revolving intermediate drum, and so arranged that the liquid collected by the said coned lip is conveyed into the filter and throughout the same under the action of the centrifugal force. Means are provided for conveying to the container the filtered cleansing liquid flowing from the filter.

Many embodiments of the invention, with various types of rubbing arrangements, are illustrated by way of example in the accompanying drawings, in which:

Fig. 1 is a diametral sectional view of a floor washing machine.

Fig. 2 is a cross sectional view, on a larger scale, of a collector device partly broken away.

Fig. 3 is an elevational View of a rubbing arrangement for the machine shown in Fig. 1.

Figs. 4, 5 and 6 illustrate a second embodiment of the invention, Fig. 4 being a diametral section similar to Fig. 1, Fig. 5 a large-scale sectional view of the collector device partly broken away, and Fig. 6, a top plan view of a driving crownpiece with one of the resilient clips hitching the said crown-piece to an intermediate drum and a rotary drum represented on Fig. 4.

Fig. 7 illustrates a third embodiment of the invention and is a diametral sectional View similar to Fig. 1.

The machine according to the invention is intended for the cleaning and the upkeep of house yards and similar paved or tiled areas, by means of hot soapy water for example. It comprises a rotary drum I having an aperture 490 at the bottom thereof. This drum is actuated by an electric motor enclosed in a casing 2, the shaft of the motor having at its lower end a friction roller 3, engaging a friction ring l fixed to the periphery of the drum I. In the embodiment according to Figure l, the casing 2, to which is articulated the handle of the machine, not shown, is formed with an arm 5, into which is screwed a hollow pivot 6, concentric with the drum and serving as a guide for an internal sleeve I. The fixed pivot 6 carries the inner races of two ball bearings 8, the outer races of which are mounted in the hub 9 of the drum.

The sleeve I is welded at its lower edge to a sheet-metal container I9, of generally toroidal form, which is coaxial with the pivot 6, and has a central depression 20, occupied by the hub 9 of the drum. The bottom of the container I9, in which a central fiow orifice 22 is formed, has under its lower face a valve seat 23,- co-operating with a cruciform metal diaphragm 24, which is pressed resiliently against the seat. The diaphragm 24 is held at its edge in a fixing ring 25.

At its upper end the sleeve I has an internally screw-threaded part 2| into which is screwed an obturating member 26, rigid with a projecting knob 21 on the arm 5. The obturating member 26 has an axial bore serving as a guide for a rod 28, at the end of which is pinned a regulating lever 29. with a helical incline 3I arranged under a cor responding incline provided in the lower extremity of the obturating member 26. A sealing washer 32 surrounds the rod 28 at the outlet from the obturating member, and a rubber ring 46 hermetically seals the joint between the obturating member 26 and the sleeve 1.

The container I9 is provided with an oblique rubber collecting tube 33, the end of which, having a thin conical edge (to be seen in Figure 1) projects into an annular gutter part I8, formed in the wall I 'I of the'rotary drum I.

It will be observed that the container I 9 can easily be removed from under the rotary drum I, after unscrewing and removing the obturating member with the knob 21, the rod 28 and the members depending thereon. If the drum I is then raised vertically, the container I9 is automatically disengaged by the sliding of the pivot 6 on the sleeve I.

The supporting arm 5 is secured to a protective cap 495 partly covering the rotary drum, this cap being provided at its lower edge with a rubber ring I0! intended for damping possible percussions of the floor washing machine against any rigid member.

The slightly coned wall of the rotary drum I has a lower external flange I69 provided with peripheral notches 45 in some of which are engaged four resilient hitching clips I 0 on the opposite ends of two perpendicular diameters of drum I. A hooked portion Iild of the clips is engaged in the notches 45 the bottom of which is adapted The rod 28 also has a collar 30 formed to provide by its upper and lower ends a radially extending abutment means 45 engaged by said hooked portion llld (Fig. l) These clips to are adapted to transmit a rotary motion to an intermediate .drum- I12 opened at both,..ends. ,and .to.a liquid collecting device 2! 2-2-|5 later to beadescribed.

Each one of the hitching clips has an horizontal part lea, disposed between two right-angle bends and jammed in a notch fiflof the inter-- mediate drum. These notches have such a shape that the intermediate drumqisilhungl onto the abutments 55' of the rotary drum I by means of the clips when the machine is lifted over the floor. The clip 58 inwardly eXtends in a-second substantially horizontal portion lilb, the .end of which is rigidly locked with a disc 20! having a central, cylindrical hollow part 252 and, in the flat wall thereof, a radial opening 293 in=which the portion 16b of the clip can yield. Each one of the clips it. has ta: radially'extendingzactuating tab fie for the purpose of disconnecting the intermediate drum I2 from the:ro.tary:drum .l.

A cork crown-:piece 2M, isfastened onto the cylindrical hollow part-2G2 by :meansmibolts 265. Sn these holts'is hooked by 'means of upstanding lugs 498 acting as hooks, afiatiring- EBSicarrying a'centrally perforated. linen sheet 231,: the under face ofwhich'is furnished with rubbing and somewhat abrasivesectors 283 made of sande'paper.

The intermediate drum H2 carrieson its :inner wall, -.a removable cardboard jacket 299, frictionally driven. An- 'accordionepleatedfilter 2-59, the folds of whichare ofrhelicoidalshape; is adhesively secured .to the bottom or: the jacketiflfi. Underneath this" filtenthere are strips 2H belonging to a conical:supportingmember' 212 for the collector. "Said strips. areadhesively secured, by their outerface-ififi to .the. jacket. 209 and have a bent,:part 2L3- (FigureZ) setoutfromthe intermediate drum'.-I I2, which part 2;i.3can easily be put out of shape, so that the supportingimember of the'collector is'able to take anoblique position with respect to the intermediary "drum. 1 12. The jacket has-a conedlowerze'dgeifiM for :the recoveryof the liquid.

The liquid-collecting lip 2l5.:=is: mademf ifiexible thermoplasticmaterial-and has upper'lugs shaped to mate in notches or sockets; '2I6-0f the supportlug-member :212.

When the machinefis runningzwith a cleaning liquid, the drops are thrown fromthe. external surface of the collector :2-l22-l5,r' by the centrifugal force and recoveredwby the :edge 2M; then they ascendbetween the ':strips;.2 H and attain the main liquid mass ilowinginto'the bottom of the'filter.

The 'helicoidal:foldingwf: the filter facilitates the circulation of. the .liquid up -:to the :top of said filter.

To replace .thezcollector: and :filter,:when:.pclluted after a cleansing Work, the operator only needs to unlock therclips EH3 :frornilthe flange Hi9 of rotary drum -l, by depressing the actuating tabs we, and raising 'the'rotarydrum. .The intermediate drum HZ-remains on thetfloor; the cardboard jacket-"2&9 together with filter 2 6 El and collector 2 IZ-Z It, can then be removed from said intermediate drum; byiaxial displacement.

The machine hereinbefore described operates in the following manner: in order to fill the container 19' with cleaning iliquidpthe 'knob (27 is turned'from right to left so that itv carriesialong withit the obturating :member'. 21% andithe rod 28 with-its-hanidle'29. enteriunserewina these d1? ferent members are removed in a single piece and the sleeve 7 is uncovered at the top. All that is than needed is to introduce the flow tube of a filler in order to be able to pour soapy water into .theetank. lithe lower fiow=orifice 22 of which is then automatically closed by th valve 23, 25.

After filling, the knob 27, together with the obvturating member 26, is screwed on again into the screw-threaded part 2! of the sleeve l, which effectstheclosure of the container I9.

The machine having been placed on the floor to beycleaned, the handle 29 for regulating the feed is turned inorder to determine the opening of the valve, due to the descending axial displacement of the-rod 28 under the action of the rotary helical incline 3 i in contact with the fixed incline --at1;the base of the obturating member 2 3. ihe

' gaged. "The ruhbingarrangement $38, while rotating, imparts to the liquid a rotary movement, which'gives-rise to acentrifugal component forcing:.the'liquid to the base of the collecting'lip 2 IS. The fil'lClll'lQI-lOIlzOf this collecting lip causes-the ascentioi" the :liquid thereon with increasing speed and its. projection to the'base of the filter 2H3, which is traversed through the action or" the centrifugal force. On leaving theifilter the filtered liquid accumulates in the gutter iii and participates-to a certain extentin the rotationoi the drum. :It is then caught up by the recoverin 500013733'3fixfld to :thecontainer anddirected along thegarciof'zasspiral. This scoop then brings the liquidbackto the container i9.

sThesecond .embodimentshown in Figures lto 6 comprises an electric motor, the casing 2 of which is formed with an armed carrying a hollow pivot?6,zconcentricawitha rotary drum l adapted tOz-bflldl'iVQIYbY the friction roller 3 engaging friction ring 4 on the periphery ofdrum i. Thepi-vot V 6;.serving asiaguide for an internal sleeve "a, carries the inner races of two ball-bearings '8, the outerwraces :of which are mounted in the hub 9 of theidrum l.

flhesleeve l is weldedat its lower edgeto a container -19 which is coaxial with the pivot 6 and :has acentral depression occupied by the said hub. .9. Thebcttom of the container 19 is'apertured'atLZZ andcarries'under its lower face a valve seat23 cooperating with acruciforin diaphragm '2'4,- resiliently pressed against the seat and held. onits edge in a fixing ring At its upper end the sleeve 1 has an internally screw-threaded part 2| into which is screwed an obturating member 25, rigid with a projecting knob 2l on the arm 5. The obturating member 26 has an axial bore serving as a guide for-a rod 28, atthe end-0f which is pinned a regulating lever 29. The rod'28 also has a collar 3% formed with ahelical-inclinefil arranged under 2, correspondingjncline provided in the lower extremity of the obturatingmemberit. A sealing washer 32 surrounds the rod 28 at the outlet from the .ohturating member, and a rubber 46 hermetically seals the joints between the obturating member 2% and the sleeve 1.

i'llhe'container i9 is provided with an oblique rubber; collectinggscoop 33 the endof which, ,havingra ithinrconicaliedge, projects intoen; annular gutter part I8, formed in the Wall ll of the rotary drum I.

All members and parts herein-before described are similar to those indicated by the same numerals referring to Fig. 1.

However, the second embodiment shown in Fig ures 4 to 6 is different from the first one in this that the liquid collecting lip made of flexible material, is mounted on a heavy rigid ring, which can be placed aslant in respect of the rotary drum, according to the shape of the surface to be cleaned.

Each resilient clip I has a strip H8, cut out in the clip and inwardly bent back in order to be resiliently pressed into a peripheral hole M9 of intermediate drum II2, the so developed pressure being sufiicient to insure the driving and holding up of the intermediate drum when the machine is being raised up.

The resilient clips H], which are used to drive the intermediate drum II 2, have many bends and their lower end is fastened to an inner plate 300, comprising a central hollow part 30! for the flowing out of the cleansing liquid. The portion I01) of the clip can give way in a radial opening 320 of the plate. Two gudgeons 392 connect this plate to a cork crown-piece 303 having a peripheral groove 3% in which are pressed resilient fastening hooks 335, riveted onto an annular sheet 305 provided with metal shavings 30? useful for rubbing the floor F to be cleaned.

The thin liquid-collecting lip 18, made of rubber, is set between a bearing surface of a heavy ring 300 and setting strips 309 provided on a thin band 3H3, forced onto the heavy ring 395. The latter carries vertical pins 3 loosely engaged in notches 3 12 of plate 390, which thus, can drive the heavy ring in rotary motion, whilst the heavy ring can be placed aslant in respect of the rotary drum. The pins 3 and corresponding notches (H2 of plate 300 are relatively rockable, torque transmitting means.

The intermediate drum H2 has a lower re-entrant edge I 60 which is intended to recover the liquid which is centrifugally thrown from the collector 49'. Besides, this edge I60 prevents the heavy ring 388 from falling down, when the machine is lifted over the surface to be cleaned.

A pleated filter H0 is engaged in the intermediate drum H2 by the interposition of a removable cardboard jacket 209; the bottom of this filter resting upon the re-entrant edge I69.

In the third embodiment, a diametral section of which is shown in Fig. 7, the shaft of the electric motor carries a driving friction roller 3 engaging a rubber ring! fixed to the periphery of the rotary drum I.

The pivot serving as a guide for an internal sleeve I, carries the inner races of two ballbearings 8, the outer races of which are mounted in the hub 9 of the drum I.

The sleeve '3 is welded at its lower edge to a container it which is coaxial with the pivot 6 and has a central depression occupied by the said hub 9. The bottom of the container I9 is apertured at 22 and carries under its lower face a valve seat 23 cooperating with a cruciform diaphragm 24, resiliently pressed against the seat and held on its edge in a fixing ring 25.

The device for filling the container I9 with cleaning liquid and for adjusting the flow of the same into the central apertured portion of the rubbing arrangement 26% is identical with that of the first and second embodiments (Figs. 1 and 4). This device therefor will not be spe-' cifically described with respect to the third embodiment of the machine.

In a like manner, the container I9 is provided with a recovering scoop 33 the outer end of which projects into an annular gutter I8 at the top of the inner wall I! of rotary drum I.

The motor casing 2 is fastened to an arm I00 having a perforation in which is engaged the hollow pivot 6 coaxial with the rotary drum I and provided with a shoulder 64. On the upper threaded end 62 of pivot 6 is screwed a guiding sleeve IIH also useful as a nut for fastening the said pivot to the arm I00 by co-operation with the shoulder 5i. The sleeve IOI is provided with a thrust-flange H02 and constitutes a stationary axis of rotation for a driving knob I03, the hollow cylindrical portion of which is provided with a large pitched external threading I04.'

The rotary drum I is partly overlapped by a protective cap I05, the central part of which is fastened to a nut I06 having a large pitch in threading engagement with threaded part I04.

A spiral spring l I6 is arranged, under the action of an initial torsional strain, between knob S03 and nut I06. The outer end of the spring IE5 is fastened to the rim 63 of the knob, the inner end, to the nut; the direction of the torque exerted by the spring H6 upon the knob I03 and the arrangement of the helical threading I04 are such that the said spring I It aims to hold the nut I06 and the cap I 05 in the highest position shown in Fig. 7. The cap I05 carries on its peripheral Wall, a damping band I07, and its lower edge I03 is useful as a disconnecting means for an inter mediate drum I I2 as will hereinafter be explained. This cap I05 is provided with a cut-out part I0 partially and loosely surrounding the motor casing 2 so as to guide the axial displacements of the said cap.

The slightly coned wall of rotary drum I has a lower flange I09 provided with peripheral notches 45 in some of which are engaged four resilient hitching clips I0, on the opposite ends of two perpendicular diameters. A hooked portion Ifld of the clips is engaged in the notches 45 the bottom of which is adapted to provide by its upper and lower ends a radially extending abutment means 45' engaged by said hooked portion l0d (Fig. 1). These clips I0 passing through cut-out parts 280 of an intermediate drum H2, (Figs. 1 and 7), are adapted to transmit a rotary motion to said intermediate drum II2 opened at both ends, and to the liquid collecting device 2I2-2I5. These clips I0 are also intended to bear a crown-piece 204 by means of a cylindrical, flanged, hollow member 23-2 and bolts 205. The crown-piece 204 is provided on its under face with rubbing sectors 203, as described with reference to Fig. 1.

Each one of the hitching clips 50 has the shape disclosed with respect to the first embodiment of the machine (Fig. 1). However, it is to be noted that the resilient clips i 0 have their outer actuating tab I0e extending across the path of the lower edge I 98 of the movable cap I05.

A jacket 209 is frictionally introduced inside the intermediate drum II2. A rotary collector ring is provided with a pliant lip M5 in contact with the surface of the floor F to be cleaned and has a set of strips 2 adhesively secured to the jacket 209. An accordion-pleated filter H3 is located above the collector 2I5 and frictionally fitted inside the jacket 209.

When the operator wants to replace the cleaning attachments in the intermediate drum H2,

he turns'the knob t3 against the action ofspring H6, so as to produce an axial, downwardsiextending displacement of th protective cap lilfiythe lower edge we of which depresses the actuating tabs We of the hitching clips it. By acting on the tabs its, the descending cap H35 disconnects the intermediate drum l i2 together with'the collector 2l22i5 from he rotary drum i. As soon as the operator releases knob M3, the spring 'i it, promoting a screwing of the guiding sleeve :Hil in the nut H35, brings the cap 565 back to its upper position by an axial displacement. The spring H5 thus produces a rotation of the knob 1% in a direction contrary to that which had brought about the coming down of cap 1&5.

Owing to the plurality of notches 5, it'becomes easy, after replacing the cleaning attachments, to dispose the rotary drum in an angular positionin. which the clips '2 ii are hitched in four such notches and permit, then to set in rotation the intermediate drum l i2.

What I claim as my invention is:

1. A centrifugal machine for cleaning a sub stantially fiat surface, comprising an electric motor journalled in a casing ('2), a supporting arm rigid with said motor casing and'having a fastening perforation, a hollow pivot (t) fastened in said perforation, a downwardly opening rotary drum adapted to be rotated around hollow pivot, torque transmitting means (3, d) disposed between. the electric motor and the rotary drum; an intermediate drum having an aperture on both ends thereof and located in said opening of the rotary drum; a crown-piece carrying a rubbing arrangement; a driving disc centrally perforated and provided with peripheral notches, said disc being fastened to the crown-piece; resilient clips hitched onto the rotary drum as well as to the intermediate drum, the one end of said clips being fixed to the driving disc; a heavy ring with a coned surface and peripheral bolts looselyinserted in said. notches of the driving disc; athin hand forced onto the heavy ring and provided with setting strips; a coned collecting lip of flexible matter, set between the coned surface ofthe heavy ring and'said strips, the heavy ring together with the collecting lip entirely surrounding the rubbing arrangement and located substantially inside said aperture of the intermediat drum; a cleansil g liquid container ('19) fastened to the supporting arm, means for conveying to said container the liquid flowing into said collecting lip and said intermediate drum through the action. of the centrifugal force, said container having a closable outlet port substantially located on the common axis of the rubbing arrangement and the collector.

2. A centrifugal machine for cleaning a' substantially flat surface, comprising an electric motor journalled in a casing (2) a supporting arm rigid with said motor casing and having a fastening perforation, a hollow pivot t) fastened'in'said perforation, a downwardly opening rotary drum adapted to be rotated around said hollow pivot, torque transmitting means (3, 4) disposed between the electric motor and the rotary drum; an intermediate drum the both ends of which are opened, concentrically disposed inside the rotary drum, said intermediate drum having a coned re-entrant edge, a crown-piece carrying-a rubbing arrangement, a centrally perforated driving plate fastened to said crown-piece, 'resilient cranked clips hitched to the lower edge :of said rotary drum and to the intermediate'drnmflthe one end of said clips being rigid with saidd'riving -plate; atheavy ring'providedwith a collecting'lip made of flexible matter and surrounding said rubbing arrangement, the maximum diameter of said heavy'ring'being substantially'greater than the opening diameter of said re-entrant edge of the "intermediate drum, means coupling said heavy ring to said driving plate, said coupling means consisting of relatively rockable elements so as to allow the heavy ring, resting on the surface to be cleaned, to place itself aslant with respect to said intermediate drum; a cleansing liquid container (l9) fastened to the supporting arm, means for conveying to said container, the liquid flow-- in into said collecting lip and said intermediate drum through the action of the centrifugal force, said container having'a closable outlet port substantially located on the common axis of the rubbing arrangement and the collecting lip.

3. A centrifugal floor washing machine comprising an electricmotor journalled in a casing, a supporting arm rigid with said motor casing and having a fastening perforation, a hollow pivot fastened in said perforation, a rotary drum having an aperture inthe bottom thereof and adapted to berotated around said. hollow pivot, torque transmitting means disposed between the electric motor and the rotary drum, an intermediate drum partly covered by the rotary drum, said intermediate drum having a'substantially circular lowor opening, a liquid collector extending entirely around the axis of said pivot and disposed substantially inside said lower opening but in spaced relation to said intermediate drum, said collector having an inclined lip normally contacting the floor, a crown-piece concentrically disposed within said collector. and provided with a rubbing arrangement, a'filter removably carried by said intermediate drum above said collector, said intermediate drum being provided with notches, resilient clips hitched onto said rotary drum and engaged in the notches of said intermediate drum, the inner part of said clips being connected to said crown piece so as to rotate the same means connecting said clips and said collector to rotate the same, a cleansing liquid container fastened to the supporting arm, means for conveying to said container the liquid flowing into the intermediate drum'through the action of the centrifugal force, said container having a closable outlet port located substantially on the common axis of the rubbing arrangement and the collector.

4. A centrifugal floor washing machine as claimedin claim 3,wherein said rotary drum has a lower peripheral flange provided with axial notches in which said resilient clips are normally .engaged'said'rotary drum also carrying radially extending abutment means, said clips comprising a hooked portion normally engaged by saidabutment and agenerally radially protruding-actuatingtab; so that said resilient clips together with said intermediate drum can be yieldingly releasedfrom the rotary drum through an axial thrusting down'upon the actuating tabs of said resilient clips.

5 A centrifugal floor machine comprising an electric motor journalled in a casing, a supporfl ing arm rigid with said motor casing and hav ng a fasteningperforation a hollow pivot fastened in said perforation, a rotary drum having an aperture in the bottom'thereof and adapted to be rotated around'said hollow pivot, torque transmitting means disposed between the electric motor and therotary drum, an intermediate drum partlycovered by the. rotary .drum; said intermediate drtimzhaving-eanzinclined :lower edge forming a circular opening, a jacket of flexible material frictionally mounted inside the peripheral wall of said intermediate drum, an annular liquid collector having an inclined lip in contact with the surface to be cleansed, said liquid collector being provided with external strips secured to said flexible jacket, a crown piece concentrically disposed within said collector and provided with a rubbing arrangement, a filter removably carried by said jacket and intermediate drum above said collector means for conveying to said filter the liquid flowing from the collector through the action of the centrifugal force; said intermediate drum being provided with notches; resilient clips hitched onto said rotary drum and engaged in the notches of said intermediate drum, the inner part of said clips being connected to said crown piece so as to rotate the same, a cleansing liquid container fastened to the supporting arm, means for conveying to said container the liquid having passed through said filter under the action of the centrifugal force, said container having a closable outlet port located substantially on the common axis of the rubbing arrangement and the collector.

6. A centrifugal floor washing machine comprising an electric motor journalled in a casing, a supporting arm rigid with said casing and having a fastening perforation, a hollow pivot fastened in said perforation, a rotary drum having an aperture in the bottom thereof and adapted to be rotated around said hollow pivot, torque transmitting means disposed between the electric motor and the rotary drum, an intermediate drum partly covered by the rotary drum, said intermediate drum being opened at its ends, a jacket of flexible material removably mounted inside the intermediate drum, a helically shaped, pleated filter in said jacket, a collector fastened in the lower part of said jacket, said collector comprising a coned supporting member provided with flexible strips stuck onto the jacket, and having sockets, a liquid collecting lip of thermoplastic material having lugs shaped to mate with the said sockets, a crown-piece concentrically mounted within said collector and provided with rubbing means at its under side, said intermediate drum being provided with notches, resilient clips hitched onto said rotary drum and engaged in the notches of said intermediate drum, the inner part of said clips being connected to said crown-piece so as to rotate the same, a cleansing liquid container fastened to the supporting arm, means for conveying to said container the liquid flowing into the intermediate drum through the action of the centrifugal force, said container having a closable outlet port located substantially on the common axis of the rubbing arrangement and the collector.

7. A centrifugal floor washing machine comprising an electric motor journalled in a casing, a supporting arm rigid with said motor casing and having a fastening perforation, a hollow pivot fastened in said perforation, a rotary drum having an aperture in the bottom thereof and adapted to be rotated around said hollow pivot, torque transmitting means disposed between the electric motor and the rotary drum, an intermediate drum partly covered by the rotary drum, said intermediate drum having a substantial circular lower opening and peripheral holes, a crown-piece carrying an abrasive and rubbing arrangement on its lower face, a driving disc centrally perforated and provided with peripheral notches, said disc being secured to the crownpiece, resilient chips hitched onto the rotary drum and having inwardly bent protruding strips engaged in said holes of the intermediate drum, the one end of said clips being fixed to said driving disc, a liquid collecting device disposed with clearance in said lower opening, said collecting device comprising a rigid heavy ring, a frustoconical collecting lip made of flexible matter and peripheral axial pins on the heavy ring, said pins being loosely inserted in said notches, a filter removably mounted within said intermediate drum, whereby said crown-piece, heavy ring and intermediate drum are coaxially disposed, a cleansing liquid container fastened to the supporting arm, means for conveying to said container the liquid flowing into the intermediate drum through the action of the centrifugal force, said container having a closable outlet port substantially located on the common axis of the rubbing arrangement and the collector.

8. A centrifugal floor washing machine comprising a casing, an electric motor journalled in said casing, a supporting arm rigid with said casing and having a fastening perforation, a hollow pivot fastened in said perforation, a rotary drum having an aperture in its bottom and adapted to be rotated around said hollow pivot, torque transmitting means disposed between the electric motor and said rotary drum, a movable cap overlapping the rotary drum and provided with a central nut, said cap having disconnecting means, a centrally open rotatable operating knob mounted on said hollow pivot and provided with a threaded sleeve in threaded engagement with said central nut, a double thrust member fastened on said hollow pivot to prevent relative axial displacement of the operating knob, whereby a rotation of said operating knob causes an axial motion of said cap, an intermediate drum covered and surrounded by the rotary drum, said intermediate drum having peripheral notches and a circular lower opening, a liquid collector extending entirely around the axis of said pivot and disposed inside said lower opening in spaced relation to said intermediate drum, flexible means connecting said intermediate drum and said collector to rotate the same, said collector having an inclined lip normally contactable with a floor, a crown-piece concentrically disposed within said collector and provided with a rubbing arrangement, a filter removably carried by said intermediate drum above said collector, resilient clips hitched onto said rotary drum and coacting with said notched intermediate drum to drive the same, said clips being connected to said crown-piece and having an outer actuating tab extending across the path of said disconnecting means of the cap, so that the latter can release said intermediate drum from the rotary drum by pushing down said tab, a cleansing liquid container fastened to the supporting arm, means for conveying to said container the liquid flowing into the intermediate drum and the filter through the action of centrifugal force, said container having a closable outlet port located substantially on the common axis of the rubbing arrangement and the collector.

9. A centrifugal floor washing machine cornprising a casing, an electric motor journaled in said casing, a supporting arm rigid with said casing and having a fastening perforation, a

hollow pivot fastened in said perforation, a rotary drum having an aperture in its bottom and adapted to be rotated around said hollow pivot, torque transmitting means disposed between the electric motor and said rotary drum, said rotary 11 drum being provided with-peripheratagial notches andwith radially extending abutments registering with said notches, an intermediate drum partly covered and surroundedv by the rotary drum, said intermediate drum having a circular lower opening, a liquid collector disposed substantially inside said lower opening but in spaced relation to said intermediate drum, said collector having an inclined lip normally contactable with a floor, a crown-piece concentrically disposed within said collector and provided with a rubbing arrangement, afilter removably carried by said intermediate drum above said collector, said intermediate drum being provided with peripheral notches, resilient clips havinga hooked portion hitched onto said radial, abutments and engaged in said notches of the rotary drum, said clips being further engaged in the notches of said intermediate drum, torque transmitting means connecting said clips and said crownpiece, said clips having an actuating tab; radially extending outside saidrotary. drum, so that said resilient clips together with said intermediate drum can be yieldingly disconnected from the rotarydr-umthrough an axial thrustingdown uponsaid actuating tabs, a, cleansing liquid-con:- tainer fastened to the supporting arm, means for conveying to said container the liquidflowing into the intermediate drum through the action of centrifugal force, said container having a closable outlet port located substantially onthe commonaxis of the rubbing arrangement and the collector.

WILLY ENGELt References Cited in the file of this patent UNITED STATES PATENTS Number Name, Date 1,211,948 Koster et ,al. Jan. 9; 191'7 1,821,715 Kuchinsky Sept. .1; 1931 2,003,216 Nadig May 28"1935 2,250,1'7'7 Boccasile July 22,1941

FQREIGN PATENTS Number Country Date 416,055 Great Britain Sept. 7, 1934 959,085 France Sept. 21, 1949 

